1. Field of the Invention
The present invention relates to a dishwasher, and more particularly, to a dishwasher having a micro filter equipped with a self-purifying function placed at a passage of a dishwasher to filter wash liquid having a high concentration of soil particles.
2. Background of the Related Art
In general, dishwashers are machines for automatically washing dishes by infecting wash liquid which contains with a detergent. Dishwashers having two dish accommodating spaces, namely, two-stage dishwashers include, as shown in FIG.1, a case 10, upper and lower racks 20 which are installed on the case 10 to accommodate dishes, upper and lower injection arms 30 which are installed on a lower side of each rack 20, a circulating pump 40 for pressing and supplying wash liquid to the respective arms 30, a drain pump 50 for draining the wash liquid, and filtering means for filtering the wash liquid.
Here, the respective arms 30 are supported by an arm holder 34 which is connected to a feed pipe 32 so as to be horizontally rotated, and a plurality of injection nozzles 301 are installed on an upper surface of the injection arms facing the respective racks 20.
In the circulating pump 40, a discharge slot is connected to the feed pipe 32 and the injection arms 30 to supply the wash liquid, and an inlet is connected to an underdrain container 60 which is comprised in the filtering means. The filtering means includes the underdrain container 6C which is provided on a lower part of a bottom surface at the inside of the case 10, and a first filter (rough mesh filter) 62 and a second filter (fine mesh filter) 64, which are installed within the underdrain container 60. The underdrain container 60 is opened toward a so-called washing space on an upper surface thereof, and connected to the circulating pump 40 on one side thereof and the drain pump 50 on a lower side thereof.
Here, the second filter 64 is configured in a shape of a pipe connected with the drain pump 50 on a lower side thereof. The first filter 62 is shaped like a filter net being provided within the second filter 64.
Operation of the aforesaid dishwashers of the conventional art is roughly divided into two stages, that is to say, a washing stage and a draining stage. In the washing stage, the washing operation is carried out in a manner that the wash liquid formed with mixture of water and detergent is pressed and supplied to the upper and lower arms 30 by the circulating pump 40, and injected to dishes d placed in the racks 20 by the injection nozzles 301.
At this time, the wash liquid injected by the injection arms 30 is collected in the underdrain container 60 on the bottom, and supplied to the injection arms 30 again by the circulating pump 40. This process is called a circulation operation. During the course of the circulation, such soil as food residues separated from the dishes d are filtered by the first and second filters 62 and 64, so as to prevent aggravated pollution of the wash liquid (see FIG.2).
When the washing stage is finished with the lapse of a predetermined period of time, the draining stage is then initiated. During the draining stage, the wash liquid is drained by the operation of the drain pump 50. As illustrated in FIG. 2, the soil with large particles is filtered by the first filter 62 and then remains within the first filter 62, thereby preventing a drain outlet from being clogged. The soil with smaller particles that passed through the first filter 62 are filtered at the second filter 64, and then discharged together with the wash liquid through the drain outlet 501 or the drain pump 50.
If the draining stage is finished and the operation of the drain pump 50 is stopped, the wash liquid still remains in a drain pipe 54 which connects the drain outlet 501 with a soil ditch. Sometimes the residual wash liquid flows backward into an inside of the dishwasher. In an attempt to prevent a backward flow of the residual wash liquid, a check valve may be installed on the drain outlet 501.
The check valve 70 prevents the backward flow of the residual wash liquid in by allowing the wash liquid in the drain pipe 54 to flow only from the drain outlet 501 to the soil ditch. The washing and draining stages are performed once during what is called one round of water filling. General, three or four rounds of water filling are conducted during one dish washing cycle. The washing and draining stages are accordingly performed, thereby enhancing efficiency in dish washing.
The conventional art, however, has a disadvantage of decreasing efficiency in washing, since a small particle soil is adhered to the second filter 64 because of structural feature of the second filter (fine mesh filter) 64, and not all of the adhered soil is discharged during the draining stage, causing a newly supplied wash liquid to be polluted.
The soil filtered by the first and second filters 62 and 64 should be removed after the washing is finally finished, however, in the conventional art the small particle soil filtered by the second filter 64 is difficult to remove although the larger particle soil filtered by the first filter 62 can be more easily removed.
Accordingly, the present invention is directed to a passage structure of a dishwasher that substantially obviates one or more problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a passage structure of a dishwasher, which can filter wash liquid in a more efficient manner by employing a predetermined passage on which a micro filter is installed and enabling the micro filter to have a self-purification capacity.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
These and other objects are satisfied by a passage structure of a dishwasher including, a circulating pump for pressing and then supplying wash liquid, an injection arm for permitting the wash liquid pressed and supplied from the circulating pump to be injected by a predetermined passage structure, an underdrain container for collecting the wash liquid injected from the injection arm and supplying the collected wash liquid to the circulating pump, during a washing stage, a soil collecting chamber having a micro filter with a fine mesh for ramifying and finely filtering the wash liquid supplied from the circulating pump and returning the same to the underdrain container, during the washing stage, a drain pump for allowing the wash liquid to be drained through a drain passage which is extended from the underdrain container, and through a connecting passage which is extended from the soil collecting chamber and connected to the drain passage, during a draining stage.
It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.